package com.util;

import org.springframework.stereotype.Component;

import javax.crypto.Cipher;
import java.security.Key;
import java.security.Security;
import java.util.Random;

@Component
public class DesUtil {
	  private Cipher encryptCipher = null;


	  private Cipher decryptCipher = null;
	  private String key;

	  
	  public static String byteArr2HexStr(byte[] arrB) throws Exception {
	    int iLen = arrB.length;
	    StringBuffer sb = new StringBuffer(iLen * 2);
	    for (int i = 0; i < iLen; i++) {
	      int intTmp = arrB[i];
	      while (intTmp < 0) {
	        intTmp = intTmp + 256;
	      }
	      if (intTmp < 16) {
	        sb.append("0");
	      }
	      sb.append(Integer.toString(intTmp, 16));
	    }
	    return sb.toString();
	  }

	public String getKey() {
		return key;
	}

	public void setKey(String key) {
		this.key = key;
	}

	  public static byte[] hexStr2ByteArr(String strIn) throws Exception {
	    byte[] arrB = strIn.getBytes();
	    int iLen = arrB.length;

	    byte[] arrOut = new byte[iLen / 2];
	    for (int i = 0; i < iLen; i = i + 2) {
	      String strTmp = new String(arrB, i, 2);
	      arrOut[i / 2] = (byte) Integer.parseInt(strTmp, 16);
	    }
	    return arrOut;
	  } 

	  public DesUtil() throws Exception {
		   super();
		  }

	  public DesUtil(String strKey) throws Exception {
	    Security.addProvider(new com.sun.crypto.provider.SunJCE());
	    Key key = getKey(strKey.getBytes());

	    encryptCipher = Cipher.getInstance("DES");
	    encryptCipher.init(Cipher.ENCRYPT_MODE, key);

	    decryptCipher = Cipher.getInstance("DES");
	    decryptCipher.init(Cipher.DECRYPT_MODE, key);
	  }


	  public byte[] encrypt(byte[] arrB) throws Exception {
	    return encryptCipher.doFinal(arrB);
	  }


	  public String encrypt(String strIn) throws Exception {
	    return byteArr2HexStr(encrypt(strIn.getBytes()));
	  }


	  public byte[] decrypt(byte[] arrB) throws Exception {
	    return decryptCipher.doFinal(arrB);
	  }


	  public String decrypt(String strIn) throws Exception {
	    return new String(decrypt(hexStr2ByteArr(strIn)));
	  }


	  private Key getKey(byte[] arrBTmp) throws Exception {
	    byte[] arrB = new byte[8];
	    for (int i = 0; i < arrBTmp.length && i < arrB.length; i++) {
	      arrB[i] = arrBTmp[i];
	    }

	    // ???????   
	    Key key = new javax.crypto.spec.SecretKeySpec(arrB, "DES");

	    return key;
	  }
	  public static String randomString(int length) {
		  Random randGen = null;
		  char[] numbersAndLetters = null;
	         if (length < 1) {
	             return null;
	         }
	         if (randGen == null) {
	                randGen = new Random();
	                numbersAndLetters = ("0123456789abcdefghijklmnopqrstuvwxyz" +
	                   "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ").toCharArray();
	                  //numbersAndLetters = ("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ").toCharArray();
	                 }
	         char [] randBuffer = new char[length];
	         for (int i=0; i<randBuffer.length; i++) {
	             randBuffer[i] = numbersAndLetters[randGen.nextInt(71)];
	         }
	         return new String(randBuffer);
	  }
	


}

